Many motor vehicles include electronically controlled seats with multiple loading configurations. For example, certain sport utility vehicles and vans include electronically controlled third-row bench seating. Third-row bench seating can include one or more seats, including for example two seats with a 60-40 split, that fold flat into or onto the floor of the vehicle to provide a generally flat surface when desired by the user.
Third-row seats can be operated by one or more DC motors to vary the inclination angle of the seatback from the stowed position to the deployed position and back again. DC motors for this purpose are typically controlled by a seating electronic control unit (ECU). The seating ECU can control the speed of the DC motor, and consequently the rate at which the seatback changes its angle of inclination, by controlling a pulse-width-modulated drive voltage. The seating ECU can also control the direction of motor rotation, typically with a bi-directional drive voltage, dependent upon the current position in relation to the desired position.
Despite the advantages of the foregoing system, there remains a continued need for the improved control of seatback DC motors. In particular, there remains a continued need to improve the detection of an obstruction or a stall condition during folding of powered seatbacks. In addition, there remains a continued need to improve the synchronous folding of two or more powered seatbacks of a bench seat, optionally in connection with a 60-40 third row seating.